The Piezoresistive Effect and its Applications

Piezoresistivity, the change in resistivity with applied stress, offers a tool for analyzing the conduction mechanism in semiconductors and also offers potential transducer applications. A discussion of this effect in semiconductors and an analysis of the fourth-rank piezoresistive tensor for two crystal symmetries are presented. The magnitude of the effect in semicondictors is tabulated, including two materials, TiO2 and PbTe, which the authors have determined to be of considerable interest. The design of devices based on piezoresistivity is discussed and illustrated by working models.